In the oilfield industry, the first area of concern for oil spills and leaks is directly at the wellhead. Despite the fact that most drilling activities are carried out in remote areas, oil spills are always a concern even more nowadays that environmental concerns have taken center stage in the discussion about the exploitation of such resources.
Many devices have been developed in order to address oil spills at wellhead. These devices are commonly referred to as stuffing box containment devices. The stuffing box containment devices are assembled in such a manner as to cover the wellhead and provide a drain to recover the oil collected in device. With varying degrees of success they have been widely implemented in the oil industry.
However, stuffing box containment devices have sensors which alert oil companies as to the fluid levels inside the containment device. In periods of rain, the containment devices collect rain as well as oil and emit false signals to oil companies which must dispatch workers to go verify the status of the containment device. Shut downs caused by rain water filling the basin are considered “false shut-downs” and are an annoyance to oil companies as they are costly. This problem has been addressed by a number of devices but each one having different and unexpected drawbacks.
U.S. Pat. No. 5,484,024 discloses an expandable and contractible covering is over the polished rod and the polished rod liner from above the polished rod liner clamp to below the stuffing box. This covering protects the environment in the event of failure of the liner or stuffing box. The covering may be quickly released from a basin below the stuffing box and contracted upward to service the stuffing box. The basin is connected to a special fitting between the stuffing box and pumping tee.
U.S. Pat. No. 5,351,753 teaches a leak containment system for a stuffing box. The cap is shaped similar to the bottom tray in that it has an outer circumferential edge that has an inner diameter slightly less than the outer diameter of a cowling to provide a snug fit therefor. A hole is disposed in the upper surface of the cap to allow the polish rod to reciprocate therethrough. The hole can be substantially equal to the outer diameter of the polish rod, allowing for tolerances during the reciprocation thereof.
U.S. Pat. No. 5,150,751 teaches a stuffing box containment device. This device contains and collects leaks from the stuffing box of a fluid producing wellhead. It comprises collection means carried by the wellhead below the stuffing box and encircling the wellhead and at least two separate upstanding hollow shapes of such cross-sectional configuration that when they are brought into abutment with one another the volume enclosed within abutting shapes encircles the wellhead and extends from the liquid collection means to above the stuffing box, said shapes having apertured top edge means which form an opening that encircles the polished rod that reciprocates through the stuffing box.
U.S. Pat. No. 8,127,838 teaches a stuffing box containment device. More specifically, the containment apparatus preferably includes a transparent lid or topper. The topper is preferably divided into half portions which can be secured together by a variety of mechanisms. In order to provide a liquid seal, each half portion provides a flange extending from opposite edges of each half portion.
U.S. 2002/0179300 teaches a stuffing box containment device intended for use in containing leaks from an oil well stuffing box which is used to seal around the polish rod which is connected to the rod string. The disclosed apparatus comprises a secondary container which encloses the stuffing box, a drain from the secondary container, and a storage container which is used for collecting any liquids which are drained from the secondary container. The secondary container has an upper seal for sealing around the polish rod, and a lower seal which seals around a member of the production tree. There is also disclosed means for injecting the escaped liquids back into the production system.
U.S. Pat. No. 5,246,067 discloses a stuffing box containment device. It has an annular head mounted on a hood including an integral upwardly extending central flange having a central opening for receiving a polished rod which extends upwardly to a pump operator and downwardly to a downhole pump. An annular seal is mounted in the hood head opening on a flange for sealing in the opening around the polished rod.
CA 2,422,876 discloses a wellhead leak containment and blowout deflection device. This device has a base capped by a detachable two-piece cover or lid. One half of the lid abuts the other half. The lid is split in two so that it may be mounted about the stuffing box and sucker rod without disrupting wellhead operation. The lid has an outwardly and downwardly flared circumferential lip forming a first, or lower, opening. The rainguard on this device is secured to the containment basin and provides no lateral movement for the polish rod.
In light of the above, there is still a need for a rainguard device for use on stuffing box containment devices which provide less installation work for the user, a safer work environment and more resistance to the wear and tear of use.